Method of recovering glycerin from fermented-molasses mash



VMay a, v1.927.

s. AK. vARNEs METHOD OF RECOVERING GLYCERINE FROM FERMEN-TED MOLASSES MASH.'

v Var/ves,

5y' /7/ls offer/Ivey It relates more,` articularly to plmash an l moval, byl istillation, of the glycerin from i Patented May 3, 197217.l

J; I 1,626,966 i This invention is in they art of`producing glycerin by the fermentation 'of molasses.

reeovern the g ycerin from the fermented et more particularly to the re- .what may be termed the concentrated slop i. e. the mass obtained by the removal of alcohol. from, and .the concentration'. of, the N lvfermented molasses mash.

' It is possible to producel glycerin-b the .fermentation o fmolasses, especiall lack strap or canemolaes; it .can be one b v fermentation in the presence of salts or a 15 k'alies. But Jwhen the recover of thegglyc- 25 to 30%of the actu x invert sugar present .in the molasses are con# erin so produced is attempte bythe ordinary distillation methods great diculties are encountered'. Ordinary black strap molassesfco'ntains about 46%'of`sucrose and .20 invert suglars which are fermentable and in` L addition as about 4% of non-fermentable V ingredients which will reduce. Fehlin'gs solution, some 20% wa'ter and the, rest gums', glorth. Usually Ifrom.

pectins, salts, and so y i sugars,\sucrose and vented to glycerin and to 45% to alcohol.

' `The fermented mash Vor beer therefore has a concentration of about-3% glycerin, 6%

f 3" alcohol and 7 to 8% gums and soforth.- On

35. is obtained. On

distillation of the alcohol and concentration of the alcohol-free beer. or fslopl a viscous j iliquid containing up to I15 .to 20% glyc i,

e y. issuing this material. if?

and alsocontainmv mostof -the salts a the ordinary type kettle vacuum still only very-indifferent yields of glycerin fare obtained,y varying from almost none. to not higher than %,'generally speaking,.of the 4Q glycerin in tlie'beer. Certain of the reasons orithis loiv recovery are as follows:

Due'to .the large amount of gums and salts.k l vpresent the'concentra'tion of the glycerin is low and as thev salts and gums are poor conrought up the mass becomes almost .solri being substantiallylike .pitchjn its physical,

'50 properties.P` `After 'part of 'the'glycerin has "distilled over the heat conductance is. so-lovv that the Irest of tlfe glycerin'vvill not betlisduced during the qdistillation` practically all fd'erwater, a`desirable concentration 'bang.`

' ii'rnon .or ucvnnme @Ircam frana: v'rnnm'rnn-.nomsns :um

Application llled Inno 14, 1922. l Serial lo. 568,179.

t covery somewhat better ssamm. x. venirne; or wumeron, nnnaw, 'auslesen non, 1. n U rom ma' N'nuoUns d conm, orwmnmeron, nnawm, a concurren or, nxmthe -svater is distilled out and the superheated steam used channels through themass.. These A conditions'are very favorable to the production of di-'glycerin and acrolein, -and in con;` sequence a large portion of \th'e glycerin is lost b deconi sitin? y A fin-ther' iiliculty is thatsince the mass `in the still becomesy'almst solid it is washed out only with considerable diiliculty. Also i the method is "not continuous and has to be carried outby the batch method. 'Ivhus, not

only is the recovery of glycerin usually. un- I der. 50% vfor Yreasons of which those Jmen-- tioned above 'are examples but also ldue to operating kdiiliculties the output per hour` is, very low..

`In avoidance of the various diliicultiescer-l .tain met ods have I.been developed 'which Icall for the precipitation of most of the gums and saltsfromthe dilute slopwlereby it has upon concentration, .been possible to get a clarified; -concentrate containing up to 35%, or bettrof gl cerin, and this concentrate on distillation asgliven a glycerin re- I t an that mentioned above.l But these *fcl arification Vmethods are expensive and complicated, rendering the devising of a less expensive and simpler method highly-desirable. Nowl have de. i

vised a method ofrecovering the 'glycerin from the ferment/ed molasses mash or beer xor, .more exactly, from the concentrated slop, by which the various diiculties'inciandy also the objectionableV features of the lclarification m'ethods are avoided; yeti highly satisfaetory recoveries are obtained, re-` coveries ofv 'glycerin from the `beer. lbeing l the gums, salts, etc., is made, as in the clari 45. yductorsof heat it takes a very long time to vheatNthe mss to the proper.- distillation tem-A i. Eeraturee' AsI lthe temperature is bein the fermentation .is straightway freed from alcohol and concentrated to af relatively' dent to'kthe `ordinary distillation. methods ue showed that 9298 %A of the i l l ,fication methods (suchicom lic'ations :being f avoided), and the thin liqui. resulting from l f Such v.masscontains, substantially @n0-65%- tilled'. Again, under the ,conditions .prc solids,.15 to 20% glycerin andthe remain point of about 135o 0.).

l cecdingly tine mist. At the same time a hot' such that' the ratio of glycerin to water is approximately 20:15 (giving a boiling This'mass, in accordance with my discovery of the possibility and practicability thereof, is sprayed in`to a chamber or still under such conditions of pressure in the chamberl and teinperature and pressure of the mass a's fed, that a portion ofl the water and glycerin of the mass bursts or flashes into vapor, exploding the viscous liquid steam into exgaseous cai'rierc'ieinically inert at tlieteinperatures involved, such4 as superheated steam, carbon dioxide, nitrogen, and fluev gas free from oxygen, and preferably exemplified by a supply of superlieated steam is introduced into the chamber tov intimately mingle with the inist; whereupon the steam the still vare desirably passed through a suitable system, as condensing means of any (preferred type, to recover the glycerin; preferably, as hereafter4 more fully described, the system includes provisions for using the heated'vapors from the distillation chamber to' concentrate the condensed dilute glycerin. The solid residue collectingy in the still descends to the bottom thereof and may be removed at intervals.

As will be understood b those yskilled in A the art, the fermented mo yasses mash is desirably distilled withsteam in a beer still to remove alcohol, the alcohol-free liquid or slop evaporated in a triple effect evaporator,

to remove water, and again evaporated In a finishingevaporator to remove additional water, thus giving the before mentioned viscous liquid or unclarified cqncentrated slop which cannot be satisfactorily treated to recover glycerin by the ordinary methods of distillation.

As to the concentration of the slop, it is for present purposes, preferably carried, as above indicated, to the point where' the ratio of the glycerin to the water is a prox!- mately 20:15. At this. concentration the boiling point of the mix-ture is suiiiciently high to permit the called for superheating' of the mixture to secure satisfactory atomization without the use of excessive pressure. To carry the concentration beyond this point necessitates the reconcentration of the distillate, due to appreciable quantities of lary, from unclariied .concentrated slop.

To these ends, and also to improve generally upon methods and apparatus of lthe V'character indicated, the invention consists in the various matters described and claimed herein.

rllie betterto describethe invention, reference is made to the apparatus illustrated in the accompanying drawings, it being understood that the invention is not restricted thereto.

Figure 1 is a conventional and somewhat diagrammatic elevational view, 0f an'apparatus assembly desirable for thev performance of the present method, and embodying the invention as it relates to apparatus, certain parts being broken out to show interiors; and Figures 2 and 3 are views of similar character of certain modifications.

In describinv the invention in detail I shall first describe the apparatus illustrated in Figure 1, then its operation in the erformance of the method, and then shall describe, the modifications illustrated in Figures 2 and 3, and their operation. Referring to Figure 1, the illustrated apparatus presents, in general, a preferably cylindrical distillation chamber, still, or evaporator, 1, a desirably cylindrical temperature-reducing or vspray-'cooling chamber 2, an evaporator 3, and a condenser, preferably a barometric condenser, 4, the elements being connected as indicated by the pipes 5, 6 and 7. The conical lower end of the distillation chamber 1 is provided with a short openended Atube\8, surroundedl by a cylinder 9 which is extended to provide a residue chamber 10 which is provided at its hopperlike bottom 11 with a closure 12. The clolll@ sure as shown is a cone bell`13 mounted on the counterweighted lever 14 fulcrumed at 15 to swing to and from closing position. At thev lower end of the chamber 1 are introduced pipes 16 and 17 for supplying steam -and slop respectively. Means, as an' oil- Il); I 4 I coil/17?. pipe 17 is provided at'its end referably of vthe provided ywith an external circulating pi ing system, designated 'generallyas25 an 1nding a pluralit of pipes, as 4`26 and 27, extended within t e chamber at points -inv termediate itsI .length and rovided` with l26 'and'27are connected with a riser pipe 28' the lower end of which is connected with a pump 29 which receives liquid from thel conical bottom 30 of the chamber 2, by the i' a is heated mwen above its boilingpoint at 'A .glycerin .bursts into vapor, ex loding the g as superheat is iii'suicient and pipe 31. A pipe 32 connects .thepipc 31 connects e p'pe 32 with the calandria 35 ofthe evaporator 3. l The evaporator 3 comprises the partitions 36 and 37 dividing the same into Athe cham' bers 38, 39 and40, with theA open-ended pipes 41 and central circulating ipe 41,pass1ng through the chamber 39 an connecting the .chambers 38 land 40, the chamber 39 with the pipes 41 presenting, of course, the calandria 35 beforeA mentioned.I The pipe 6 and, as before noted,'the pipe 34 communicate with the 'chamber 3 9. Atfits bottom the chamber 38 is provided with the. pipe 42, valved at 43, connecting. the'chamber with the storagel receptacle v44 for-the recovered glycerin and' 1s 'also provided with a pipe -45,-valved at l45, connecting the chambery and the receptacle 33." A vent in chamwith a stoliage ,receptacle.33, and a pipe 34 4ber 39 for non-condensible gases `is indicated at 46. The barometricconden'ser 4 is shown as provided with awater supply pipe 47, a tail ipe 48, and an outlet 49, for non- `condensib e gases.v To the outlet' pipe 49 is conn'ecedY the vacuum pump 50. In practicing the method of the present invention, with the aid of the described apparatus, the unclarifed concentrated slo 1s taken from the storage tank 19, where it-A has been heated by the coil 20,v and is dclivered at high' pressure, eng. desirably between` 250 and 350 pounds per Square inch gauge, to the coil 17l in heater 22 where it the (preferably atmospheric) pressure in chamber 1. As the lslop leaves the nozzle 2,3 in chamber 1 a-portion of the water and stream into-a state of exceeding y fine mist'.

The ingoing slop temperature should referably be substantially 210l C., asatis actory working range being -"190l to l220" C; and temperatures up to 230"` C. beingworkables If the temperature ldrops toA 1'10.A C. the

or atomization results; if on the other and the tem# remoyed at' intervals through the' bottom .sprayed intothe chamber 1),' pass i'nto the perature rises to 240 C. an action similar to oil cracking-may occur, causin deposits in ythe-,pi ing.. It 1s lhighly .'advisa ,le to man- I -tain t re pressure at the nozzle higher'`V than -visable for slop at temperatures up to 230 C; as, otherwise, partial distillation or flashing in the piping mayotcur resulting in de.- posits vand clog ing. lThe lower the' temperature, .of 4c ou se the flower the pressure can' be. It is preferable -to operatefat about 250 pounds nozzle pressure for the temperature range indicated above. J

Simultaneously with the, introduction of the slop, steam at atmospheric pressure and superheated byvpassa e4 through the sup/erheater 18 is introduce through the i e. 16, and passes up through the open smiledp tube 8 and intimatelymingles with the finely to 450 C. the residue becomes too dry and may clog the bottom or throat of the chamber 1, 4and also some decomposition of thc glycerin results as-well as decomposition ofv the organic matter `of the residue which 'increasesthe Volume oinon-condensible gas .A to 'be disposedof. I c

Asthe volatile matters are leaving through the pipe 5, the non-volatile constituents drop 1 to the bottom of the chamber' 1, or iiow down the sides,and pass through the tube 8'into the" residue chamber 10 from which they are opening of the chamber.l 1 The volatile .products leaving through the pipe 5, and comprising a dilute mixture of? -glycerin vapor in superheated steam andV carr ing a very'small portion of entrained' soli residue (less-than 2% ofthe total solids spray coolingdevice 2 and are met by v,the

while if the temperature' is allowedv to go, 4.

liquid spray issuing from the'nozzles 27,-' i

26. `A-portion of this liquid yv'aporizes and reduces the temperatureof the -superheated entering-vapors substantially to saturation,

at the same timescrubbing the vapors free of entrained residue. (The temperature in the spray-cooling device 2 -may be about 105110 9;). The scrubbed vapors de-- Amisted slop, the two meetingat the top of- 90 i thetube 8 or thereabouts. The steam gives up heat'to the suspended mist, vaporizing the l part through the'pipe 6 and, entering the chamber 39 Lof the evaporator 3, surround the pipes 41 (and 41). The Weight of vapor, now substantially saturated, leaving the chamber 2 exceeds. the weight of vapor enteringA by the amount of liquid evaporated from'the liquid sprays. The vapors are condensed inwthe. relatively cool chamber 39 while the non-condensible gases are vented through the pipe 46. The condensate, a dilute solution of glycerin yin Water, is removed through the pipe 34 and delivered to storage 33. lThe unvapprized portion of/the sprayed liquid leaving the nozzl s 26,'27,is

rator 3,-'the -fglow bein controlled by .the

' valve 45n it being evi e'nt that operations may be started with the storage tank 33 initially filled, say from a previous operation, and the valve Llhmay be set to pass only excess liquid, thus keeping the tank 33 full. The liquid level in the evaporator 1s ucarried at suche. height as fto\completely or partially lill the tubes 41 and 41"". 'A vacu- `carried within the chamber 40, reducing lthe Lboiling temperaturel below the temperature of the vapors surrounding the tubes,'and the liquid in the tubes -is Yboiled by the heat c given upby the condensation of ,the vapors.

The steam produced is separated in steam spacey 40 from the remalnlng liquid and` J@passes through pipe ,7 to thee condenser 4 where it is condensed yand is dischargedthrough the taiil pipe48l As before indicated, wateris supplied to the condenser at 47 and non-condensible gases are drawn off, by the vacuum/pump-O, through the pipe 49. Theponcentrated liquid ypasses down through the circulating pipe 41- to the reservoir 38 and is recirculated through the tubes until it is sufficientlyconcentrated, whereupon it-is I,withdraw/n,through the pipe 42 toffthe resU ceiver 44,.the Vflow beingcontrolled by the lva'lve 43.

. `Thus itwill bejlseen/tliat the' present invention ,provides `for the ready recovery of `glycerin from fermented black strap molasses l -'mash o r beer and, more definitely, from the unclariied concentrated slop obtained by the removal of #al ohol from the beer axfd by concentration of the alcoholrfre'eqliquid or slopA without ,clarification of, the slop.

Thus black strap. molassescan satisfactorily be used/as the source'of fermentable maum, for example. about 27 in. of mercury, isv

terial, revious difficulties of glycerin recovery aving been overcome. This is a partlcularly desirable result. as black strap molasses is 'the cheapest and one of the few materials which will allow of the production pf fermentation glycerin which ,can compete lwith lycerin fromA oils, lfats andso forth.

, Re erring now to the modified apparatus illustrated in Figures 2 and 3, and, first, to

that shown in Figure 2, the apparatus there shown comprisesY afractionating column, designated generally as 51, and a barometric condenser 52, the two being connected by the pipe 53, and the condenser being connected with a vacuum pump 54. It will be under- 80 stood that the column is to be connected with a spray distillation chamber, as 1, provided, as prevlously described, with. steam inlet,

Vslop feed, and so on','the`apparat1is now in question taking the place of the various ele- '95 ments beyondtle vapor pipe 5 as illustrated in Figure 1,'and the va or pipe 5 being coni nected with the base 5 of the fractionating column lasindicated. The'column come prises a plurality of perforated plates 55, l Iand desirahly, a plurality of coollng pipes J 56 suitably -arranged within the columnand supplied wlth cooling medium, as water, from any suitable source. The pump 54 ,is

operated Qtocreate a vacuum suiiicient to draw the vapors through the column and the columnis cooled wby radiation from the shell, `or if called for, by the cooling pipes 56, to hold theltop of the column at thelboiling pointof water vat the rvacuum main- 109` tained at the top of'the column. Under these conditions, in accordance with the usual operation of fractionating columns, thereis withdrawn from thebase thereof,

by way of thelpipe 5K7 leading to the receiver 1.05`

58, a concentrated mixture of glycerin' and Water, while /steam'strip'ped free offglycerin is discharged through the pipe 53.

` Referring to the larrangement shown in Figure 3/t e sme gislike that of Fi ure 2, l1

for use wit a spray distillation cham er, asf A1,' equipped as before indicated and for sub- 4, stitution for the elements beyond the vapor pipe 5 in Figure 1.r The illustrated structure'comprises a shell 59 khaving the parti`5 115 tions 60 and 61 to divide the same into f chambers 62, 63 and `64,'the partitions carry l lng the-open-ended pipesV 65'. Cooling medium, as water, is supplied to the chamber 63 by the pipe 66 and drawn olf at 67.y The 120 lupper' chamber, 64, His furnished with an escape pipey 68/ Spray nozzles in suitable number, as 69 and '70," are mounted in the chamber `62 and su plied with liquid pumped ythrough the pipe I7) its supply from the pipe 73. T is pipe 73 is connected with the base 74 of the shell and drains into a 'receiverv 7 5, it being evident /thatfthe illustrated draw-off valvefrom the receiver 75 may be kset to discharge only ex- 1370 superheat 1s removed and the vaporsv scrubbed and cooled to substantially saturated condition by the partial evaporation of the liquid sprayed. The vapor is condensed in the pipes 65, surrounded by the cooling medium in the chamber 63, and the con-.

densed mixture of glycerin and water drains down through the tubes 65, into the pipe 73, and so tothe storage receiver 75. In the operation the coolingis maintained suoli that the temperature` in the chamber. 64 is held somewhat belowl 100 C, (the pipe 68 leading to atmosphere).

IIf desired, the operation and arrangements may be such that steam. strippe glycerin passing from the system shall be reused in the chamber 1, saving ex ense. For example, with the apparatus of 1 gure 2 condensation of the steam may beomitted andthe steam piped to the superheater 18: correspondingly, the apparatus of Figure 3, may be so operated that the steam, instead of being condensed, passes on, and such steam be conveyed to the superheater 18.

While chambers, as 1, of various dimensions'may beused, I have found a. 'chamber having a cylindrical portion about27 feet in length and about 5 feet in diameter satisfactory. As mentioned above, I prefer to Work with atmosphericv pressure in the chamber 1, since, among other advantages, it does not lcall for so large achamber as would be required for working satisfactorily under vacnum. f

I claim: =1. In the art of .producing lycerin by the fermentation of molasses,- t e steps of dividing unclarified, concentrated slop into minute portions, exploding the so-divided slop into mist in contact witha hot gaseous carrier chemically inert at the temperatures involved while maintaining a temperature to quickly vaporize theglycerin from the slop, and condensing the evolved glycerin vapors.

2. In the art of producing lycerin by the fermentation of molasses, t esteps of spraying into a chamber at atmospheric pressure uuclariiied concentrated `slop, previously heated under positive pressure. sufiiciently high to retain it in liquid state and at a temperature sufficiently higher than the boiling pointV 'at atmosphericl presin theslop to cause` explosion of the sprayed slop into-mist upon release of said positive d of pressure, simultaneously spraying into the chamber steam superheated to a higher temperature than that of the slop, thus callsing quick vaporization of the exploded slop, and condensing the evolved vapors.

3. In 4the art of producing glycerin by the fermentation of molasses, the steps of highly heating unclarified concentrated slop While applying a pressure thereto suiiicient to prevent exploding of the slop priorto the introduction thereof into the hereinafter named chamber, spraying said slop, so

heated and under pressure, into a chamber at a pressure sufiiciently low to give a pres-l sure drop sufficient to cause explosion of thesprayed-slop vinto mist, and into Contact with steam, with the slop and steam heated to maintain a temperature to quickly vaporize the glycerin from the mist, and condensing the evolved glycerin vapors.

4. In the art of producing glycerin by the fermentation of molasses, the steps of spraying unclarified concentrated slop at a temperature substantially between 190 to 230 C. and ata pressure ofat least substantially 225 pounds per square inch, into a chamber at substantially atmospheric pressure, and into contact with superheated steam at substantially atmospheric pressure and at temperature substantially between i;

390 to 430 C., and condensing the evolved glycerin vapors. f

- 5. In the art of producing glycerin by the fermentationof molasses, the steps of spraying unclarifi'ed concentrated slop at a temperature of substantially 210 C. and at a pressure of substantially 250 pounds per square inch"into a chamber at substantially atmospheric pressure, and into contact with superheated steam at substantially atmos- 'pheric pressure and at a temperature of substantially 410 C., and condensing the 'i evolved lycerin vapors.

6. In t e art of producing glycerin by the fermentation of molasses, in that process which comprises dividing unclarified concentrated slop into minute portions, exploding.l the so-divided slop into mist in contact yvith a hot gaseous carrier while maintaining a temperature to quickly vaporize the glycerin and water from the slop z-the step ics lll)

ofspraying, into the said glycerin and water vapors, a relatively cool liquid mixture of glycerin and water directly and intimately into said vapors to reduce them to substantially saturation temperature, and

lcondensing the so-saturated vapors. sure of the glycerin-water mixturev present In testimonyvwhereof -I aix my signature.

SAMUEL K. VARNES. 

